This invention relates generally to online systems, and more specifically to determining social proximity between users of an online system.
An online system offering content for consumption by their users often recommends content items to its users to keep the users engaged with the online system. For example, an online system identifies content items to recommend to users based on a content item's popularity or the content item's similarity to content items with which a user previously interacted. However, a content item that is popular among some online system users may not be interesting to another online system user because the user does not share common interests with the online system users with which the content item is popular. Accordingly, determining which content items to recommend to a user based merely on the popularity of content items across an online system's entire user base often results in recommending content items to users who are not interested in the recommended items.